python - Change default return value of a defaultdict *after* initialization -


is there way change default_factory of defaultdict (the value returned when non-existent key called) after has been created?

for example, when defaultdict such as

d = defaultdict(lambda:1)

is created, d return 1 whenever non-existent key such d['absent'] called. how can default value been changed value (e.g., 2) after initial definition?

assign new value default_factory attribute of defaultdict.

default_factory:

this attribute used __missing__() method; initialized first argument constructor, if present, or none, if absent.

demo:

>>> dic = defaultdict(lambda:1) >>> dic[5] 1 >>> dic.default_factory = lambda:2 >>> dic[100] 2

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